<p>The Group enables you to make a selection of units. This selection of units can be
used very simply, like just counting units within various "segments", but it can
and must be used to run a Job. The nice thing about groups is that they are very
flexible, not like profiles which have a static nature.

<b>Add/Change/Delete/Inspect</b>
<p>In the Group page, you can add/change/delete/inspect a particular Group. In order to
create a Group, you have to select the Unit Type, enter a Group name, and add a
description.</p>

<p>It is possible to create a hierarchy in the Group structure, by setting a parent Group. The
Profile selection will then be inherited from the parent Group, and cannot be changed. If
a Group has not defined a Profile, the selection is All Profiles, that is all Units within the
given Unit Type.</p>

<p>The actual seletion of units is made by adding parameters to the group. They act like simple
search-clauses (parameter1 = 'foo' and parameter2 != 'bar'). Note that each parameter is AND'ed
together, there is no OR in use here. The search critera from the parents are also AND'ed into
the search in the same fashion. Combine this with the possiblity to create your own System
parameters in the Unit Type page and then populate these parameters with information feeded
from your own CRM/BSS-system, then you will have a truly flexible grouping system, allowing you to
create any kind of group you need.

<p>A Group cannot be deleted if it is a part of a Job that is currently running. The current
size field denotes the number of Units that are currently part of the
Group. It can in some cases take some time to load the Group page due to the
calculation of this number of Units.</p>

<p>Advanced mode allows you to create a time-rolling group. Such a group changes a specific
parameter criteria every hour or every day. The criteria is then set to either the current
hour or the current date. If offset is specified, the hour or date is moved forward in time 
the number of days specified. The purpose of such a group is only evident when combined with
a syslog event (see GROUPSYNC syslog event), since units can be "tagged" with the current 
hour or date, and then "fall" into a certain group. This can in turn be used to both Jobs and
statistics/monitoring.

<b>Overview</b>
<p>If the Group has set a parent Group, then it will be displayed In the Group overview in a
tree structure that looke like parameter hiearchy lists.</p>

<p>You can filter Groups based on their name and Profile. If you have a lot of top level
Groups and dependent children, you would use this filter to only retrieve a certain set of
Groups.</p>

<p>You can filter the selection of Units by configuring a set of Group parameters. Adding and
updating Group parameters is done almost in the same way as we have seen on the Unit
Type and Profile pages. The only difference here is the Operator column, that defines if
this is a likeness or an unlikeness filter parameter.</p>


